退耕还林对岷江上游高山聚落区生态服务价值变化的影响

Effects of Grain for Green Project on Changes in Ecosystems Service Values of Alpine Settlement Area in the Upper Reaches of the Minjiang River

岷江上游地处青藏高原向四川盆地过渡地带,是长江上游生态屏障核心区和成都平原重要水源地,生态服务价值变化是界定该流域生态位势的重要判据。基于1999和2009年SPOT4-5二期遥感数据,以山区聚落生态位为研究单元,采用土地利用类型单位面积生态系统服务价值赋值法,阐明岷江上游退耕还林前后的山区聚落生态位内部生态服务价值变化特征及其动因。研究结果表明:1999—2009年10 a间,山区聚落生态位生态服务总价值增加0.18×108元。1)农田面积减少108.20 km2,其生态服务价值减少1.1×108元,源于山区聚落人口空心化导致所需农田食物供给这一生态服务功能下降;2)森林面积增加23.19 km2,其生态服务价值增加0.75×108元;3)草地面积增加49.77 km2,其生态服务价值增加0.53×108元。森林/草地生态服务价值的变化,表明国家退耕还林工程生态环境效益显著。4)建设用地面积增加9.16 km2,其生态服务价值增加仅为0.0057×108元,这与城镇化背景下高半山区聚落内人走楼空态势相吻合。

The upper reaches of the Minjiang River in west China provides huge ecosystem services owing to its localized geological characteristics, which are important to keep sustainable ecosystem development in the upper reaches of the Yangtze River and the Chengdu Plain. It is an important proof for defining ecological potential by quan- tifying the change in ecosystem service value. In order to quantitatively analyze and compare the changes in ecosys- tem service values caused by Grain for Green Project, economic value of ecosystem services in the Minjiang River during 1999--2009 was estimated by form of ecosystem service values coefficients for different land use categories. The data sets of spatial-temporal land use in mountainous settlement ecological niches during 1999--2009 were ob- tained from two-period remote sensing causes which led to changes in values information. The changes in ecosyste were also revealed. In general, The m service values were calculated and the changes in land use of mountainous set- tlement ecological niches were obvious during 1999--2009, and the total ecosystem service value had been in- creased by 0.18 × 108 yuan（RMB） from 1999 to 2009. Detailed results are as following： 1 ） As the area of agricul- tural land decreased by 108.20 km2, the corresponding ecosystem service value decreased by 1.1× 10^8 yuan. It suggested that the decrease in ecosystem service value of a agricultural land is related to decrease in population and food demand. 2） Once the area of forest increased by 23.19 km2, the ecosystem service value increased by 0.75× 10^8 yuan. 3 ） Once the area of grassland increased by 49.77 km2, the values increased by 0.53 × 10^8 yuan. Com- paring the changes in land use of ecological niches and ecosystem service values, the areas of forest and grassland and their ecosystem service values evidently increased in 2009 after implementing Grain for Green Project. It indi- cated that Grain for Green Project had some effective influence on protecting ecosystem services. 3 ） When the area of construct land increased by 9.16 km2, the ecosystem service value increased by 0.0057 × 10^8 yuan. The increased magnitude of ecosystem service value of construct land is smaller than that of forest and grassland, which is relative to population decreasing and emigration. Anyway, the research on the ecosystem service value in this study site could not only prove scientific proof for establishing ecological compensation, but also indicator for quantifying the effect of Grain for Green Project.